PROGNOSTIC VALUE OF COGNITIVE TESTS AND THEIR COMBINATION IN PATIENTS WITH CHRONIC HEART FAILURE AND REDUCED LEFT VENTRICULAR EJECTION FRACTION

Abstract

Impaired cognitive function (CF) is common among patients with CHF and is an additional factor impairing the quality of life, adherence to treatment, and hence the clinical prognosis in this category of patients.

The aim of this work was to study the prognostic significance of individual cognitive tests, as well as their combination in patients with CHF with a reduced left ventricular ejection fraction (LV EF).

Materials and methods. The study was conducted in the Department of Heart Failure of National Scientific Center "M.D. Strazhesko Institute of Cardiology" National Academy of Medical Sciences of Ukraine, in the period from 01/01/2016 to 04/27/2018. A total of 124 patients with CHF between the ages of 18 and 75 years, II-IV functional classes by NYHA were examined. The cognitive function was assessed using the Schulte test, Mini-Mental State Examination scale (MMSE); HADS scale. Cognitive dysfunction (CD) was considered as MMSE ≤26 points. To construct the survival curves and the onset of the combined critical event (death or hospitalization), the Kaplan – Meier method was used, the significance of the differences between the curves was determined using the log-rank criterion. Differences were considered statistically significant at p <0.05.

Results. The MMSE scale was highly informative regarding the prediction of survival and the onset of a combined critical event (death or hospitalization) in patients with CHF and reduced LVEF even after correction of the compared groups by age and functional class according to NYHA (p=0.025 and p=0.049, respectively). Using the same sample, Schulte showed low prognostic significance regarding survival and reliable informativeness regarding the onset of the combined critical event, which, however, was leveled after correcting the compared samples by age and functional class NYHA (p=0.798 and p=0.240, respectively). The inclusion in the prognostic algorithm of estimating the sum of points on the HADS depression scale allowed increasing the degree of reliability of differences between the compared groups of patients with CD and without CD in terms of both long-term survival and the onset of a combined critical event (death or hospitalization) (p=0.006 and p=0.001 respectively).

Conclusions. The MMSE scale is informative regarding the prediction of survival and the onset of a combined critical event in patients with CHF and reduced LVEF. Schulte's test does not have the prognostic information indicated above, however, the inclusion in the algorithm of the sum of points on the HADS depression scale allows to increase the degree of statistical confidence in the compared groups.